A CommonInputSection is a section containing all common symbols.
That was an input section but was abstracted in a different way
than the synthetic input sections because it was written before
the synthetic input section was invented.
This patch rewrites CommonInputSection as a synthetic input section
so that it behaves better with other sections.
llvm-svn: 286053
It turned ou that we actually want to call std::for_each even if
threading is supported. Unless --thread is given, LLD shouldn't use
more than one threads.
llvm-svn: 286004
If multi-threading is disabled, parallel_for_each will automatically
fall back to std::for_each, so we don't have to do that ourselves.
llvm-svn: 285968
Previously, we added strings from DynamicSection::finalize().
It was a bit tricky because finalize() is supposed to fix the final
size of the section, but adding new strings would change the size of
.dynstr section. So there was a dependency between finalize functions
of .dynamic and .dynstr.
However, I noticed that we can elimiante the dependency by simply
add strings early; we don't have to do that in finalize() but can do
from DynamicSection's ctor.
This patch defines a new function, DynamicSection::addEntries, to
add .dynamic entries that doesn't depend on other sections.
llvm-svn: 285784
Instead of storing a pointer, store the members we need.
The reason for doing this is that it makes it far easier to create
synthetic sections. It also avoids reading data from files multiple
times., which might help with cross endian linking and host
architectures with slow unaligned access.
There are obvious compacting opportunities, but this already has mixed
results even on native x86_64 linking.
There is also the possibility of better refactoring the code for
handling common symbols, but this already shows that a custom class is
not necessary.
llvm-svn: 285148
We were fairly inconsistent as to what information should be accessed
with getSectionHdr and what information (like alignment) was stored
elsewhere.
Now all section info has a dedicated getter. The code is also a bit
more compact.
llvm-svn: 285079
When doing a relocatable link the .ARM.exidx sections with the
SHF_LINK_ORDER flag set need to set the sh_link field to the executable
section they describe. We find the appropriate OutputSection by
following the sh_link field of the .ARM.exidx InputSections.
The getOutputSectionName() function rules make sure that when there are
multiple .ARM.exidx InputSections in an OutputSection they all have the
same sh_link field.
Differential revision: https://reviews.llvm.org/D25825
llvm-svn: 284820
Some MIPS relocations used to access GOT entries are able to manipulate
16-bit index. The other ones like R_MIPS_CALL_HI16/LO16 can handle
32-bit indexes. 16-bit relocations are generated by default. The 32-bit
relocations are generated by -mxgot flag passed to compiler. Usually
these relocation are not mixed in the same code but files like crt*.o
contain 16-bit relocations so even if all "user's" code compiled with
-mxgot flag a few 16-bit relocations might come to the linking phase.
Now LLD does not differentiate local GOT entries accessed via a 16-bit
and 32-bit indexes. That might lead to relocation's overflow if 16-bit
entries are allocated to far from the beginning of the GOT.
The patch introduces new "part" of MIPS GOT dedicated to the local GOT
entries accessed by 32-bit relocations. That allows to put local GOT
entries accessed via a 16-bit index first and escape relocation's overflow.
Differential revision: https://reviews.llvm.org/D25833
llvm-svn: 284809
MIPS GOT consists of some parts: local, global, TLS entries. This change
separates calculation of MIPS GOT index and offset of the corresponding
part of the GOT. That makes code a bit clear and allow to extend number
of parts in the future.
llvm-svn: 284750
In this patch partial gdb_index section is created.
For costructing the .gdb_index section 6 steps should be performed (details are in
SplitDebugInfo.cpp file header), this patch do first 3:
Creates proper section header.
Fills list of compilation units.
Types CU list area is not supposed to be supported, so it is ignored and therefore
can be treated as implemented either.
Differential revision: https://reviews.llvm.org/D24706
llvm-svn: 284708
Use size_t instead of ELFT::uint for the string table offset. If the
linker is built 32-bit, it can't write an output file larger than 2GB.
Other code in this area uses size_t as well.
llvm-svn: 284680
Summary:
Reclaiming the name 'CachedHashString' will let us add a type with that
name that owns its value.
Reviewers: timshen
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25644
llvm-svn: 284434
The .ARM.exidx sections contain a table. Each entry has two fields:
- PREL31 offset to the function the table entry describes
- Action to take, either cantunwind, inline unwind, or PREL31 offset to
.ARM.extab section
The table entries must be sorted in order of the virtual addresses the
first entry of the table describes. Traditionally this is implemented by
the SHF_LINK_ORDER dependency. Instead of implementing this directly we
sort the table entries post relocation.
The .ARM.exidx OutputSection is described by the PT_ARM_EXIDX program
header
Differential revision: https://reviews.llvm.org/D25127
llvm-svn: 283730
This spreads out computing the hash and using it in a hash table. The
speedups are:
firefox
master 6.811232891
patch 6.559280249 1.03841162939x faster
chromium
master 4.369323666
patch 4.33171853 1.00868134338x faster
chromium fast
master 1.856679971
patch 1.850617741 1.00327578725x faster
the gold plugin
master 0.32917962
patch 0.325711944 1.01064645023x faster
clang
master 0.558015452
patch 0.550284165 1.01404962652x faster
llvm-as
master 0.032563515
patch 0.032152077 1.01279662275x faster
the gold plugin fsds
master 0.356221362
patch 0.352772162 1.00977741549x faster
clang fsds
master 0.635096494
patch 0.627249229 1.01251060127x faster
llvm-as fsds
master 0.030183188
patch 0.029889544 1.00982430511x faster
scylla
master 3.071448906
patch 2.938484138 1.04524944215x faster
This seems to be because we don't stall as much. When linking firefox
stalled-cycles-frontend goes from 57.56% to 55.55%.
With -O2 the difference is even more significant since we avoid
recomputing the hash. For firefox we go from 9.990295265 to
9.149627521 seconds (1.09x faster).
llvm-svn: 283367
It is pretty easy to get the data from the InputSection, so we don't
have to store it.
This opens the way for storing the hash instead.
llvm-svn: 283357
Do not merge sections if generating a relocatable object. It makes
the code simpler because we do not need to update relocations addends
to reflect changes introduced by merging. Instead of that we write
such "merge" sections into separate OutputSections and keep SHF_MERGE
/ SHF_STRINGS flags and sh_entsize value to be able to perform merging
later during a final linking.
Differential Revision: http://reviews.llvm.org/D25066
llvm-svn: 283300
LLD does not update relocations addends when generate a relocatable
object. That is why we should not write a non-zero GP0 value into
the .reginfo and .MIPS.options sections. And we should not accept input
object files with non-zero GP0 value because we cannot handle them
properly.
llvm-svn: 282716
In case of linking PIC and non-PIC code together and generation of a
relocatable object, all PIC symbols should have STO_MIPS_PIC flag in the
symbol table of the ouput file.
llvm-svn: 282714
The BYTE, SHORT, LONG, and QUAD commands store one, two, four, and eight bytes (respectively).
After storing the bytes, the location counter is incremented by the number of bytes
stored.
Previously our scripts handles these commands incorrectly. For example:
SECTIONS {
.foo : {
*(.foo.1)
BYTE(0x11)
...
We accepted the script above treating BYTE as input section description.
These commands are used in the wild though.
Differential revision: https://reviews.llvm.org/D24830
llvm-svn: 282429
This is PR30386,
SORT_BY_INIT_PRIORITY is a keyword can be used to sort sections by numerical value of the
GCC init_priority attribute encoded in the section name.
Differential revision: https://reviews.llvm.org/D24611
llvm-svn: 281646
Previously, all input files were owned by the symbol table.
Files were created at various places, such as the Driver, the lazy
symbols, or the bitcode compiler, and the ownership of new files
was transferred to the symbol table using std::unique_ptr.
All input files were then free'd when the symbol table is freed
which is on program exit.
I think we don't have to transfer ownership just to free all
instance at once on exit.
In this patch, all instances are automatically collected to a
vector and freed on exit. In this way, we no longer have to
use std::unique_ptr.
Differential Revision: https://reviews.llvm.org/D24493
llvm-svn: 281425
This simplifies error handling as there is now only one place in the
code that needs to consider the possibility that the name is
corrupted. Before we would do it in every access.
llvm-svn: 280937
This patch allows static linking of TLS code. To do that it fixes
GOT entries initialization.
If TLS-related GOT entry created for a preemptible symbol i.e. has
a corresponding dynamic relocation, leave the entry initialized by zero.
Write down adjusted TLS symbol's values otherwise. For the adjustments
calculation use offsets for thread-local storage.
https://www.linux-mips.org/wiki/NPTL
llvm-svn: 280914
It looks like MIPS dynamic loader does not support RELCOUNT tag.
Both gold/bfd linkers does not emit this tag on MIPS. I will investigate
the problem further but for now it is better to behave like GNU linkers.
llvm-svn: 280630
FreeBSD's libstdc++ build (used on tier-2 architectures) uses GNU ld's
-f <name> option, which sets the DT_AUXILIARY field to the specified name.
Multiple -f options may be specified and the DT_AUXILIARY entries
will be added in the order in which they appear.
Patch implements that option.
Differential revision: https://reviews.llvm.org/D24139
llvm-svn: 280475
The primary use of build-id is in debugging, hence omitting debug
sections when computing it significantly reduces its usability as
changes in debug section content wouldn't alter the build-id.
Differential Revision: https://reviews.llvm.org/D24120
llvm-svn: 280421
Previously we used LayoutInputSection class to correctly assign
symbols defined in linker script. This patch removes it and uses
pointer to preceding input section in SymbolAssignment class instead.
Differential revision: https://reviews.llvm.org/D23661
llvm-svn: 280348
Rafael Espindola